Not in city buses, but flixbuses, school buses, &c.|

These: https://www.usabuscharter.com/uploads/4/3/6/1/43615417/setra...

In my town only the intercity ones used to have them, but these days all the city buses have them too. I don't mind using the seatbelt, but their design isn't optimal - they're hard to put on, particularly if you're wearing a large jacket. A lot of fumbling is required.

In Germany at least it depends on the type of bus. Long distance / travel busses (Google translates it to "coach") are required to have seatbelts, regular "city busses" don't.

As a general rule, buses that go on motorways (ie intercity, mostly) tend to have them; others usually don't.

The first few rows of seats sometimes have those, but not all the rows after that